The present invention relates to vehicle suspension systems. In another aspect, this invention relates to a new and improved level load leaf spring drop axle.
In the construction of vehicular trailers or the like, level load drop axles have been used for suspension systems. For purposes of description in this application, the phrase "level load" axle is meant to include axles which provide a uniform side-to-side drop to a vehicle even though the loading is eccentric. These systems are of particular use in vehicular trailers wherein tipping to one side or the other can cause the load to be unstable. One of these systems is illustrated in the U.S. Pat. to Misic, No. 2,724,589, issued Nov. 22, 1975.
Although these prior art systems have served their purpose, they have not been entirely satisfactory under all conditions of service. Therefore, according to the present invention, an improved level load leaf spring drop axle is provided wherein a single mounting bracket is utilized to attach both the spring and the axle to the vehicle and wherein a leaf type spring is used having a spring constant that increases as the deflection of the wheels increases. In addition, the axle is formed with parallel-spaced crank arms with the leaf spring positioned between the crank arms whereby interference between the crank arms and spring is eliminated and maximum travel of the crank arms is permitted. In addition, eccentric loading on the crank arm is minimized by placing the spring follower between a pair of parallel spaced crank arms.
The advantages and other features of the present invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following Detailed Description when considered in connection with the accompanying Drawings in which: